An apparatus includes a sampling probe having a first portion and a second portion. The first portion is configured to penetrate inside a wall of a duct having an inner chamber that is configured to carry a gas stream containing particulate matter therethrough. The first portion is further configured to divert a sample of the gas stream from the inner chamber of the duet to the second portion that extends from the wall of the duct opposite the inner chamber. The second portion of the sampling probe is configured to direct the sample of the gas stream in a first direction with a second direction corresponding to a direction of the gravitational force of the earth. A first ray corresponding to the first direction forms an angle with a second ray corresponding to the second direction. The angle is less than 90 degrees.

In order to secure the dilution ratio accuracy of diluted exhaust gas while making it possible to accurately measure the mass of PM, an exhaust gas measurement system that has a diluted exhaust gas flow path through which the diluted exhaust gas produced by diluting exhaust gas flows and collects particulate matter in the diluted exhaust gas by a filter provided in the diluted exhaust gas flow path for measurement is adapted to include a bypass flow path that branches from the upstream side of the filter in the diluted exhaust gas flow path and merges with the downstream side of the filter; and a separation flow rate control part that while flowing the diluted exhaust gas through the filter, controls the separation flow rate of the diluted exhaust gas flowing through the bypass flow path.

Methods and apparatus for an exhaust demand control system for measuring one or more contaminants at one or more exhaust locations within one or a plurality of exhaust ducts or plenums served by an exhaust fan system. Example systems and methods can include sensing the one or more contaminants within the one or more exhaust duct locations using a multipoint air sampling system having one or more sensors and flow control elements, comparing contaminant concentration measurements from the one or more of said exhaust duct or plenum locations against an action level to create a fan setback signal, and ensuring sensor accuracy and reliability by implementing a sensor protective mode when the contaminant concentration measurements from the one or more exhaust locations exceeds an action level.

In order to make it possible to accurately analyze particulate matter contained in exhaust gas without making a system large-scale or expensive, the present invention is adapted to include an exhaust gas flow path through which exhaust gas of an internal combustion engine is introduced, a branch flow path that branches from the exhaust gas flow path, a first analyzer that is provided downstream of a branch point of the branch flow path in the exhaust gas flow path and measures particulate matter contained in the exhaust gas, a second analyzer that is provided in the branch flow path and measures the particulate matter contained in the exhaust gas, and a temperature control mechanism that controls the temperature of the first analyzer.

A device dilutes an aerosol without distortion due to loss of particles, especially liquid particles, on wall surfaces. An inlet pipe feeds aerosol as inlet aerosol and an outlet pipe has an inlet opening arranged at a finite distance from an outlet end of the inlet pipe. An annular space surrounds an end area of the inlet pipe. A clean gas line opens, via an outlet opening, into the annular space. A process is provided including feeding the aerosol as inlet aerosol through the inlet pipe, with particle-free clean gas fed to an end area of the inlet pipe and mixed with the fed inlet aerosol into a diluted outlet aerosol. The diluted outlet aerosol is sent to a measuring device. The mass flow of the aerosol sent to the measuring device and that of the added clean gas are maintained at a fixed ratio.

A process dilutes an aerosol by feeding an input aerosol through an inlet pipe surrounded by an annular space to a first mixing stage. An output aerosol leaves purified via an outlet as a particle-free clean gas. The particle-free clean gas is fed to the annular space upstream of the outlet and is mixed with the aerosol. A mixing stage includes an inlet pipe feeding aerosol as inlet aerosol. A downstream purification device purifies outlet aerosol leaving the mixing stage via an outlet pipe to form the particle-free clean gas. A mass flow controller and a pump suction off the outlet aerosol from the outlet pipe. A return line, for the clean gas, leads upstream into the annular space.

A monitoring system for monitoring a pipeline can include a sampling unit, a spectroscopy system, and a waste handling system. The sampling unit can include a sampling point for capturing a representative sample of a fluid flow in the pipeline. The spectroscopy system can be configured to chemically analyze the representative sample with respect to components of the fluid flow. Additionally, the spectroscopy system can be configured to detect a corrosive component of the fluid flow. The waste handling system can remove the representative sample from the spectroscopy system.

Methods and apparatus for an exhaust demand control system for measuring one or more contaminants at one or more exhaust locations within one or a plurality of exhaust ducts or plenums served by an exhaust fan system. Example systems and methods can include sensing the one or more contaminants within the one or more exhaust duct locations using a multipoint air sampling system having one or more sensors and comparing contaminant concentration measurements from the one or more of said exhaust duct or plenum locations against an action level to create a fan setback signal.

To provide an exhaust gas analysis apparatus that, without the need to greatly change the flow rate of diluted exhaust gas passing through a filter, can change the flow rate of exhaust gas in the diluted exhaust gas passing through the filter with good followability to reflect weighting, and accurately measure PM, the exhaust gas analysis apparatus is adapted to include: a collection part that collects particulate matter in sampling exhaust gas partially splitting from original exhaust gas or in the diluted exhaust gas resulting from diluting the sampling exhaust gas with diluent gas; and a split flow ratio control mechanism configured to, in accordance with a vehicle driving mode set in compliance with predetermined regulations, change a split flow ratio that is the ratio of the split flow rate of the sampling exhaust gas to the total flow rate of the original exhaust gas.

In order to provide an exhaust gas sampling apparatus that makes it possible to simplify the entire system using a simple structure flow rate control mechanism having a small variable flow rate range as well as making the accuracy of an exhaust gas dilution ratio higher than before, the exhaust gas sampling apparatus is configured as an exhaust gas sampling apparatus that makes a multistage dilution. In addition, the exhaust gas sampling apparatus is configured to, given that a dilution ratio determined by an n-th diluter in a dilution flow path at an n-th stage as a final stage is R, make dilution ratios determined by diluters in dilution flow paths at the respective stages other than the n-th stage as the final stage substantially equal to (R+1).